1. Field of the Invention
The present invention generally relates to a method for manufacturing a golf club head and, more particularly, to a casting and pressing method for manufacturing a golf club head having an embedded heterogeneous material which provides an enhanced engagement between the heterogeneous material and a cast material different from the heterogenous material.
2. Description of the Related Art
To meet the requirements of a low and deep gravity center, to reduce the reactive force acted upon the user when hitting the golf ball, and to improve the feeling of the user hitting the golf ball, a golf club head is embedded with a heterogeneous material that is different from the material of the golf club head in order to adjust the gravity center and the hitting feeling. The heterogeneous material is usually arranged on the toe, sole, heel back, hosel or striking faceplate of the golf club head.
Please refer to FIG. 1. A conventional method for manufacturing a golf club head having an embedded heterogeneous material includes preparing a striking faceplate 91, forming a protruded edge 911 that protrudes from an end of the striking faceplate 91, and welding two nuts 92 to a rear face of the striking faceplate 91. The conventional method for manufacturing the golf club head further includes forming two screwed holes 931 on a surface of a counter weight 93, aligning each screwed hole 931 with a respective nut 92, and fastening the aligned screw hole 931 and nut 92 with a screw 94. Thus, the counter weight 93 is engaged with the striking faceplate 91. As shown in FIG. 2, a club head body 95 is cast by a dewax method, and the protruded edge 911 of the striking faceplate 91 is embedded in the cast club head body 95. The counter weight 93 is enclosed and installed in a space jointly defined by the club head body 95 and the striking faceplate 91, forming a golf club head 9. Such a conventional method for manufacturing a golf club head having an embedded heterogeneous material can be seen in Taiwan Patent No. 288346.
Before the club head body 95 is formed by casting, the shell mold used in the casting procedure needs to be heated to a high temperature in order to maintain the flowability of a molten metal liquid that was poured into the shell mold. However, since the striking faceplate 91, the counter weight 93 and the club head body 95 are made of different materials (i.e. the melting points of the striking faceplate 91 and the counter weight 93 are higher than that of the club head body 95), the heterogeneous materials (i.e. the striking faceplate 91 and the counter weight 93) in the shell mold are easily oxidized during the heating process of the shell mold. Thus, the engagement strength between the casting material and the heterogeneous materials is reduced. In addition, since the casting material and the heterogeneous materials have different thermal expansion coefficients, the casting material may disengage from the heterogeneous materials when cooling down.
In light of the above, it is necessary to improve the conventional method for manufacturing the golf club head having the embedded heterogeneous material.